350 lag and pop on acceleration

I have a '71 Monte with 350 and the G.M. performance fast burn heads that were used in the build article about a year ago. have an edelbrock750 carb with a edelbrock mechanical street pump. I amusing a performer intake manifold. it has a lunati voodoo cam:219"/227'.I am using the flowtech tri y headers with 2.5 dual exhaust with flowtech afterburn mufflers straight through design. It still has the points distributor in it with new points last spring, adjusted them about two months ago. Yes need a hei dist. couple guys told me could be starving when i stomp on it that is why it lags. Don't get what the pop noise is though. any help would be great.
Montes Rule

Is the "pop" coming through the carb? After it "lags" does it smooth out? Where is the base ign. timing (no vaccum hooked up) set at? How about total mechanical timimg? Is the vaccum source to the distributor "manifold". The symtoms describe either fuel, ignition, or possibly both. Changes that make the engine breathe better (cam, intake, headers) will almost always call for more ign. timing. Did it have this problem before the new equipment was added? A 750 cfm carb, whether it be a Holley, Edelbrock or whoever is too big for a 350 cid street engine that is making it's peak power at 5000 rpm. Post some more details and we will help you figure it out. JW.

i had a 600cfm on it and the performance guy at burt greenwald told me to move up to a 750 because those fast burn heads like a lot of fuel. the timing was not set with a digital timing lite like it should have been.(i know big mistake) it is set on the timing marksclose to the end of them towards the pass side of motor. dont remember if that is before or after. yes after i stomp it and it lags let out of it and it goes fine. did not do it with the old 600 carb and the original heads. had the same intake, cam, headers, and exhaust before the heads and the 750.
Montes Rule

My advise is if you have the original 600, try it and see if the problem goes away. If it does then your 750 is out of tune besides being too big. If the problem still persist's, then look into the ign. timing further. You will need a timing gun to get it just right. Start out at 10 deg. BTDC ( no vaccum ). It wouldnt hurt to get a curve kit and follow the instuctions to give your engine the correct curve throughout the entire rpm range. JW.

This sounds like crossed plug wires which would explainthe popping & lagging. did the problem begin afterreplacing plugs or plug wires? or when you had the distributor out of the engine? Check your firing orderand make sure the wires are on the cap in the correctorder and that the wires are going to the correct plug.I think the firing order is: 1-8-4-3-6-5-7-2 and the#1 cylinder is at the driver's side front of the engine.also check initial timing. you may need 12 + degreesdepending on your mods and altitude where you live.

i actually have a stock 91 350 in my truck and it is popping back through the carb. Ive talked to several older mechanics in my area and they all told me to check my gaskets and my timing i timed the truck to day and it still does it. i leaning towards the float in the carb. cause when the gas moves back in fourth in the carb it thinks its not full pouring more gas into it and then burning the excess causing the popping. if anyone can tell me if that is a possibility let me know

What was the condition of the heads?, who adjusted valves? what were valves adjusted too? I agree with other posts, timing needs to be tits and carb is way to big for a street machine, I thought recent article in CHP said something about edlbrock carb issue low to mid hesitation and popping due to covered venturi nozzles? anyone????

I've read thing as well about the edel 750 (afb) being unpredictable and my comparisons to dyno tests back this up - sometimes the Edel 750 gives a great showing, other times it behaves like a sick 2 barrel.

Do you recall which issue of CHP? I don't quite follow the covered nozzles, they are covered on the AVS but not the AFB style....

I've experienced this popping too even on a well tuned engine, every time when I swap carbs it goes away. 750cfm is too big, but if the carb is well tuned it still shouldn't pop, it should just run soggy slow.It sounds like about 600cfm is right anyway so I agree I'd just go back to a known good carb and try it, then maybe play with the 750 to see if it will ever run right, tune jets, rods, etc.

thanks guys i am going to try the carb switch and this winter going to get the hei small cap but right now had to get the garage and the car ready for the winter. one car only so it is in hibernation mode now but thanks for the ideas.
Montes Rule